im looking to run larger tire on my 4runner....its an SR5 that can with 15" rims and they look absolutely AWFUL and WAY to small for the car.....i want to run 31 x 11.5 15 or maybe 32 (doesnt matter as though my family owns a local tire shop)......are these possible with no lift and stock rims if i use hub spacers to get proper back spacin on rim

 

Welcome to the forum

99s also had 16 inch rims so there may be a bigger variety in tire sizes in the 16s than the 15s. Then you can step up to the larger brakes and woah Nelly it is off to the races spending your dough....

Gearing may become an issue-if your vehicle came from the factory with the 15" tires then it is geared that way.

You can certainly upgrade to a 16x7 factory rim and even 16x8s will likely fit but you will learn quickly everything affects everything...

Your father should understand all about this- running a tire shop. I imagine he would strongly recommend you stick with a stock tire size or a mild upgrade.
To get specific the heavier weight of a 16" wheel and tire increases wear on suspension pieces like tie rods and so on. Please do not upgrade your wheel size without upgrading your brakes as well. You might be stunned to see some statistics on how much further braking distances increase when wheels are oversized and brakes are not.

A 31x10.50x15LT tire comes from many manufacturers and is affordable and a good compromise of street ride and "beefy" looks. An aggressive tread pattern may be all you really need to get by.